hle: services: Fix a crash with improper NVFlinger lifetime management. (#4977)

* hle: services: Fix a crash with improper NVFlinger lifetime management.

- This crash would happen when attempting to shutdown yuzu early on in boot.

src/core/hle/service/service.h

@@ -29,7 +29,11 @@ namespace Service {
 
 namespace FileSystem {
 class FileSystemController;
-} // namespace FileSystem
+}
+
+namespace NVFlinger {
+class NVFlinger;
+}
 
 namespace SM {
 class ServiceManager;
@@ -181,10 +185,17 @@ private:
     }
 };
 
-/// Initialize ServiceManager
-void Init(std::shared_ptr<SM::ServiceManager>& sm, Core::System& system);
+/**
+ * The purpose of this class is to own any objects that need to be shared across the other service
+ * implementations. Will be torn down when the global system instance is shutdown.
+ */
+class Services final {
+public:
+    explicit Services(std::shared_ptr<SM::ServiceManager>& sm, Core::System& system);
+    ~Services();
 
-/// Shutdown ServiceManager
-void Shutdown();
+private:
+    std::unique_ptr<NVFlinger::NVFlinger> nv_flinger;
+};
 
 } // namespace Service